Zay jeffries



Z. JEFFRIES.

INTERNAL COMBUSTION MOTOR.

APPLICATION FILED OCR-23,1916. RENEWED NOV. 8.1919.

1,347,479, Patented July 20,1920.

UNITED STATES railrnu'rv OFFICE.

ZAY anrrnrns, or EAST CLEVELAND, onro, ASSIGNOR To THE ALUMINUM CASTINGS COMPANY, or CLEVELAND, care, A conroanrron or care.

rnrnannncoianusrron Moron.

Application filed October 23, 1916, Serial No. 127,152. Renewed November 8, 1919. Serial No. 336,733.

To all whom it may concern:

Be it known that I, ZAY Jnrrnrns, a citizen of the United States, residing at East Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Internal-(J0mbustion Motors, of which the following is a specification, reference being had therein to the accompanying drawing.

This invention relates to an improved cylinder and piston construction for internal combustion motors.

The use of light weight aluminum alloy pistons in internal combustion motors has been attended by certain drawbacks. In particular it has been found necessary to provide a relatively largeclearance between the piston and the cylinder wall because the alloy metal of the piston has a substantially higher coefiicient of expansion than cast iron which was previously used as the piston material. This large clearance has given rise to piston slap,while the motor is starting and warming up, and also to an undue leakof lubricating oil into the combustion chamber, such excess of oil giving rise to serious carbon troubles. In addition, motors with aluminum alloy pistons have tended to run cooler than those with iron pistons because the higher thermal conductivity of the aluminum alloy results in a somewhat more rapid transfer of heat to the cylinder wall.

The main object of the present invention to overcomethe foregoing difficulties and this is accomplished providing for the cylinder a cylindrical liner made of an alloy metal having a.coeilicient of expansion :uaproximating that of the aluminum alloy of the pistons and constructed and arranged in the ironcylinder so as to permit an expansion of the liner corresponding to that of the piston.

A further object of the invention is the pro "ision of a composite cylinder compris ing a cylinder casting and a liner therein constructed and arranged to permit of the expansion of the liner in relation to thecylinder casting in a manner to control the working temperature of the motor.

Specification of Letters Patent.

Patented July 20, 1920.

In order that the invention and the man ner of carrying it out may be clearly understood, I will now describe one form of construction embodying the invention.

In the accompanying drawings Figure l is a transverse vertical section of one of the cylinders of an engineembodyiron and comprising the cylinder wall 1,

the water jacket 1, suitable intake and exhaustv valve passages, and the upper crank case section 1 The cylinder casting has its main cylindrical chamber bored out to receive a tubular liner 2 which is made of metallic alloy having a coefficient of thermal expansion approximatelyequal to that of the aluminum alloy commonly employed to make light weight pistons. There are different alloys more or less closely meeting these requirements, but I prefer to use an aluminum alloy having a composition adapting the liner to resist the wear of the piston, because the coeificientof thermal expansion of such liner is practically identical with that of the piston material. The liner 2 has its inner surface accurately bored out to afford a suitable bearing surface for the piston. At its upper end the lineris formed with an outturned flange 2 which fits, with a slight radial clearance, in a corresponding countersink in the upper end of the cylinder casting. At its lower end the liner is formed with an external enlargement or collar 2 which fits the bore of the cylinder casting.

' cylinder casting.

If desired, the adjacent walls of the cylinder casting and liner may be given a plain cylindrical finish so that when the expension of the liner occurs its surface is brought into" contact with the surrounding cylinder wall throughout its entire area. I prefer, however, to form the adjacent walls so that only a part of the exterior surface of the liner is brought in close contact with the cylinder wall when the expansion occurs, and the transfer of heat to the water jacket is correspondingly checked and the motor kept at a suitable Working temperature. To this end, in the construction shown, I have depressed or cut away a part of the outer surface of the upper part of the liner lying adjacent the water jacket and have correspondingly depressed or cut away the entire outer surface of that part of the liner extending from the water jacket down to the collar 2 This formation of the outer wall of the liner may readily be accomplished by machining and preferably I form the depression in the upper part of'the sleeve by machining a continuous spiral groove 2 thus forming a square spiral thread 2, the outer surface of which comes into contact with the cylinder wall when the liner expands. The amount of clearance provided between the square thread and the surrounding cylinder wall will depend upon the size of the cylinder and various other factors.

The upper end of the cylinder is closed by a head casting designated as an entirety by 3, this casting having a water jacket 3 communicating in the usual manner with the water jacket 1 of the cylinder casting.

The combustion space a formed in the head casting has an extension l which communicates with the inlet and exhaust passages through valve controlled openings in the usual manner; in the drawing the exhaust valve is shown at 5 and it will be understood that the inlet valve is in that part of the stiucture which does not appear.

The sleeve or liner 2 may be secured in the cylinder in any suitable manner but I prefer a construction of the character shown in which the liner is held by the cylinder head 3, the latter-being firmly secured to the cylinder casting as usual. by bolts (not shown). As stated above, the fiange 2 of the liner fits the countersink of the cylinder casting with a slight radial clearance. This clearance is provided to allow the upper end of the liner to expand radially when heated, the expansion of the metallic alloy liner being greater than that of the iron cylinder casting. To insure an accurate centering of theupper end of the liner in the bore of the cylinder casting without interfering with the expansion referred to, I form the flange 2 with a series of radial grooves 2, and to the head casting 3 secure a corresponding number of depending round pins 6, each arranged to fit in one of the radial grooves 2. These pins prevent lateral displacement bodily of the upper end of the liner without interfering with its radial expansion. The lower end of the liner is not heated as highly as its upper end and the enlargement 2 can be relied upon to center the said lower end, the bore of the liner at its lower end being made slightly larger than at other points, if necessary, to accommodate any slight deformation of the lower end of the liner that may result from its expansion against the less expansible iron.

In Fig.1 the pins 6 are shown cylindrical and the grooves 2, correspondingly, with vertical sides. If desired, this construction can be modified as shown in Fig. 5 where the pins 6 are tapered at their lower ends and the grooves 2 formed with inclined sides. With this latter construction a very nice fit can be secured between the pins and grooves by properly setting the pins.

'7 designates a piston arranged to reciprocate in the cylinder liner in the usual manner, being connected by connecting rod 8 with the crank 9 of the engine shaft 10. This piston is made of light weight metallic alloys preferably aluminum alloy such as is now in use for this purpose. he piston is provided with packing rings 11 of any preferred form and construction, and, in other respects, the piston may be of any suitable form and construction.

I-Ieretofore in motors with aluminum pistons a relatively large clearance has been provided for the piston, but in my improved construction the piston is fitted to the bore of the liner nearly if not quite as closely as a cast iron piston would be fitted to'the bore of a cast iron cylinder.

In the operation of my improved motor. the cylinder liner when cold is entirely out of contact with the surrounding cylinder wall except possibly at the collar 2"; but, as the piston and liner absorb heat from the combustion gases, they both expand until the working temperature is reached, at which point, or slightly before it, the outer surfaces of the projecting thread 2 are broughtinto close contact with the cylinder wall. Until this latter contact is established, the liner is thermally insulated from the surrounding cylinder wall by the interposed envelop of air and consequently the cylinder and piston rise quickly to working temperature and the motor is correspondingly easy to start. As soon as contact between the liner and the surrounding cylinder wall is established, excess heat begins to be conducted to the water jacket and the parts are thus kept at suitable working temperature.

A composite cylinder, properly designed and constructed in accordance with my invention, has a peculiar automatic governing action on the working temperature of the engine; for if the temperature falls to a certain value the resultant contraction of the cylinder parts causes the external surface of the liner to draw away from the wall of the cylinder castingso that the'conduction of heat to the latter is at once checked and the working temperature of the motor tends to build up again. This action, as stated, is automatic in its nature.

As has been stated, the piston, when the parts are cold, has only the minimum clearance necessary for smooth operation; and, inasmuch as both piston and cylinder liner expand together when the motor heats up, no seizing of the pistonv occurs but, on the contrary, the small initial clearance is maintained substantially constant. I therefore entirely avoid the objectionable pistonslap and oil pumping which has characterized prior motors with iron cylinders and aluminum pistons.

As I have already indicated, the clearance provided between the outside diameter of the liner and surrounding cylinder wall will depend upon the form and dimensions of the motor and is preferably to be determined in each case experimentally, as is also the area of contact between the liner and cylinder wall. My experience indicates that in most cases the clearance in question will run between eight and fifteen thousandths of .an inch for cylinders running from three to four inches in diameter.

Those skilled in the art will understand that various changes in the forms and proportions of the parts may be made in carrying out my invention. The construction herein set forth is for purposes of illustration and explanation and in no sense intended as a limitation of my invention.

What I claim is:

1. In an internal combustion motor, the combination with a composite cylinder comprising an iron casting with a cylindrical wall surrounded by cooling means, and a cylindrical liner secured concentrically withthe iron of the said casting and having its external diameter less than the diameter of the inner wall of the casting to afford a clearance between the liner and casting adapted to be taken up by the expansion of the liner when heated by the internal combustion within the motor, of a piston arranged to reciprocate in the liner and made of a light weight metallic alloy having a coefiicient of thermal expansion greater than that of the iron of the cylinder casting.

2. In an internal combustion motor, the combination with a composite cylinder comprising an iron casting with a cylindrical wall surrounded by cooling means, and a cylindrical liner secured concentrically Within the said cylindrical Wall, the said liner being made of a metallic alloy having a higher coefficient of thermal expansion than the iron of the said casting and having its external diameter less than the diameter of the inner wall of the casting to afford a clearance between the liner and casting adapted to be taken up by the expansion of the liner when heated by the internal combustion within the motor, of a piston arranged to reciprocate in the liner and made of a light weight metallicalloy having a coefficient of thermal expansion approximately equal to that of the liner alloy.

3. In an internal combustion motor, the

prising an iron casting with a cylindrical wall surrounded by cooling means, and a cylindrical liner secured concentrically Within the said cylindrical wall, the said liner being made of aluminum alloy and having its external diameter less than the diameter of the internal wall of the casting to afford a clearance between the liner and casting adapted to be taken up by the expansion-of the liner when heated by the internal combustion within the motor, of an aluminum alloy piston mounted to reciprocate in the liner with a normal working clearance when the parts are cold.

4. In an internal combustion motor, the combination with a composite cylinder comprising an iron casting with a cylindrical wall surrounded by cooling means, and a cylindrical liner secured concentrically within the said cylindrical wall, the said liner being made of a metallic alloy having a higher coeflicient of thermal expansion than the iron of the said casting and having its external diameter less than the diameter of the inner wall of the casting to afford a clearance between the liner and casting adapted to be taken up by the expansion of the liner when heated by the internal combustion within the motor, and part of one of the adjacent surfaces of the cylinder wall and liner being recessed to form heat insulating space between the cylinder wall and combination with a composite cylinder comliner, of a piston arranged to reciprocate in the liner and made of a light weight metallic alloy having a coefiicient of thermal expansion greater than that of the iron of the cylinder. casting.

5. In an internal combustion motor, the combination with a composite cylinder comprising a casting with a cylindrical wall surrounded by cooling means, and a cylindrical liner secured concentrically within the said cylindrical wall, the said liner being made of metallic alloy having a higher coeflicient of thermal expansion than the metal of-the said casting and having its external diameter less than the diameter of the inner wall of the casting to afford a clearance between the liner and casting adapted to be taken up by the expansion of'the liner when heated by the internal combustion within the motor, of a piston arranged'to reciprocate in the liner and made of a metallic alloy having a coefficient of thermal expansion approximately the same as that of the liner alloy.

6. A composite cylinder for internal combustion motors comprising a casting with a cylindrical wall surrounded by cooling means and a cylindrical liner secured concentrically within the said cylindrical wall, the liner having its external diameter less than the diameter of the inner wall of the clearance between the liner and casting adapted to betaken up by the expansion of the liner when heated by the internal combustion within the motor.

8. A composite cylinder for internal combustion motors comprising a casting with a cylindrical wall surrounded by cooling means and a cylindrical liner secured c011- centrically within-the said cylindrical wall,

the liner having its external diameter less than the diameter of the inner wall of the casting to afford a clearance between the liner and casting adapted to be taken up by the expansion of the liner when heated by the internal combustion within the motor, and part of one of the adjacent surfaces of the cylindrical wall andliner being recessed to form heat insulating space between the cylinder wall and liner.

made oi metalhaving a higher coefiicient of thermal expansion than the metal of the said casting and having its external diameter less than the diameter of the inner wall of the casting to afford a clearance between the liner and casting adapted to be taken up by the expansion of-the liner when heated by the internal combustion within the motor, and part of one of the adjacent surfaces-of the cylinder wall and liner being recessed to form heat insulating space between the cylinder wall andliner. 7

10. In an internal combustion motor, the combination with a composite cylinder comprising a main cylindrical iron wall, cooling means on the outer side of said wall, and a cylindrical liner secured concentrically within the said cylindrical wall, the said liner being madeof a metallic alloy having a higher coeflicient or" thermal expansion than the iron-of the said wall and having its external'diameter less than the inner diameter of the said wall'to afiord a clea *ance between the liner and wall adapted to be taken upby the expansion of the liner when heated by the internal combustion within the motor, of a piston arranged to reciprocate within the liner and made of a light weight metallic alloy having a coeflicient of thermal expansion greater than that of the iron cylinder wall.

11. In an internal combustion motor, the combination with a composite cylinder comprising a main cylindrical wall, cooling means on the outer side of said wall, and a cylindrical liner secured concentrically within the said wall, the said liner being made of metallic alloy having a higher coefiicient of thermal expansion than the metal of the said cylindrical wall and having its external diameter less than the inner diameter of said wall to afford a clearance between the liner and wall adapted to be taken up by the expansion of the liner when heated by the internal combustion within the motor, of a piston arranged to reciprocate in the liner and madev of a metallic alloy having a coefiicient of thermal expansion approximately the same as that of the liner alloy.

12. A composite cylinder for internal combustion motors comprising a main cylindrical wall, cooling means on the outer side of said wall, and a cylindrical liner secured concentrically within the said cylindrical wall, the liner having its external diameter less than the inner diameter of the said wall to alford a clearance between the liner and wall adapted to be taken up by the expansion of the liner when heated by the internal combustion ithin the motor.

13. A composite cylinder for internal combustion motors comprising a main cylindrical Wall, cooling means on the outer side of said Wall, and a cylindrical liner secured concentrically Within the said Wall, the liner being made of metal having a 10 higher coefficient of thermal expansion than the metal of the said Wall and having its external diameter less than the inner diameter of said cylinder Wall to afi'ord a clearance between the liner and Wall adapted to be taken up by the expansion of the liner when heated by the internal combustion Within the motor.

In testimony whereof I hereunto affix my signature.

ZAY J EFFRIES. 

